Remote control apparatus for radioreceivers



Dec. 24, 1935.

L. W. REINKEN REMOTE CONTROL APPARATUS FOR RADIORECEIVERS Filed Sept.26, 1929 phhbblh llv/lllllllll Z Y: ii/iii LOU/S W. PE/NKE/Y.

INVENTOR BY fiMM ATTORNEY Patented Dec. 24, 1935 PATENT OFFICE REMOTE@ONTROL APPARATUS FOR RADIORECEIVERS Louis William Reinken, Brooklyn, N.Y., assignor, by memo assignments, to Federal Telegraph Company, Newark,N. J a corporation of California Application September 26, 1929, SerialNo. 395,352

14. Claims.

, a radio receiver from a remote point.

Another object of "the invention is to control a radio receiver from aremote point, the control being effected by the use of exceptionallysmall currents.

A still further object of the invention is to control a radio receiverfrom a remote point by the use of a polarized relay.

Afeature of the invention is that vacuum tubes are employed in a bridgecircuit to control a polarized relay, which in turn controls theactuating motive means which may be of any suitable type such as shownin Kolster co-pending application 310,006 filed October 3, 1928.

The present invention consists substantially in the construction,combination, location and relative arrangement of parts which provide animproved remote control system for radio receivers and. apparatus of alike nature. In the system disclosed in the application above referredto, energy suflicient to operate the motive means was transmittedthrough the remote control unit and over the conductors leading thereto.In the present system a comparatively small amount of energy is requiredat the remote point to control the operation of the tuning apparatusthereby providing an extremely safe system as well as a. dependable one.This system further provides an electrical blocking circuit effectiveduring tuning to prevent intermediate stations being received inconjunction with a slow acting braking system.

The invention will be more fully understood by reference to theaccompanying drawing in which:

Fig. 1 is a diagrammatic schematic drawing of a system embodying theprinciples of the invention;

Fig. 2 is a view of the motor-braking system, showing a pendulum brake;

Fig. 3 is a schematic circuit drawing showing the use of a single vacuumtube amplifier to control a polarized relay; and,

Fig. 4 is a'schematic circuit drawing showing the use of a push-pullvacuum tube amplifier to control a polarized relay.

Similar numerals refer throughout the several views.

In the apparatus and circuit shown in Fig. 1, a high resistancepotentiometer 5 is attached to to similar parts I a 3-wire cablecomprising conductors 6, fl, and 8, which terminates in a highresistance potentiometer 9. A variable contact l located onpotentiometer 9 is mounted to rotate with a gang condenser unit ll ofany well known type. The condenser unit may be driven by an eddy currentmotor l2 through any type of drive such as a pulley and cord system l3.

Potentiometer 5 is provided with a plurality of contacts l4, and amovable arm IS in series with 0 a lamp l6 and a polarized relay H. Therelay H is provided with an armature l8 which closes the energizingcircuits of alternating current relays l9 or 20 by contacts 2| and 22,respectively, according to the direction of current flow through relayH. The relays l9 and are provided with armatures 23 and 24,respectively, which close circuits through contacts 2! and 2B,energizing motor coils 25 and 26, respectively, from a source of currentreceived 20 over conductor 35 and plug 34. The plug may be attached tothe H0 V. house supply of altemating circuit.

The motor I2 is provided with a pendulum arm 3! and a contact arm 38adapted to lit 25 into a series of notches 39 in a driving disk 40 whendrawn therein by a spring 4| and released by the energization of a coil36. Coil 36 is energized over conductor 35 when either relay l9 or 20 isenergized, releasing the arm 38. To make the braking .action of thependulum more effective, a weight 44 may be mounted on the arm 31. Stops45 limit the rotation of the arm 31.

Returning to the circuit, a definite voltage is placed across thepotentiometers 5 and 9 by a battery 29 in series with a resistance 30.Battery 3|, which is in series with battery 29, provides plate potentialfor a vacuum tube 33 which may be any tube of a radio receiver althoughpreferably a radio frequency amplifier. A winding 32 is a primary of acoupling transformer and winding 4 is a secondary of another couplingtransformer. The direct current grid circuit of the tube 33 includes aresistance 43 and resistance 30. The latter resistance unit supplies thenormal grid biasing potential by the drop across it which is caused bythe current flow from battery 29 through potentiometers 5 and 9. Thealternating current circuit for the tube 33 is through a condenser 42.

A description of the operation of the circuit is as follows:

When it is desired to tune the receiver, adjustable arm I5 with itsassociated contact I4 or one of the other contacts I is closed. If themotor driven potentiometer arm l-ll is not at a position correspondingto the contact which has been closed, current will flow from the battery29 through the resistance 30 and through the coil of the relay IT. Thedirection of the current flow through the coil will depend upon theposition of the arm II) with respect to the contact which has beenclosed. 'For instance, if the arm I is at a lower position and one ofthe upper contacts It has been closed, current will flow in a definitedirection through the relay I! while if. the arm I0 is in an upperposition and one of the lower contacts I4 is closed, current will flowin the opposite direction through the relay l'l. According to thedirection of current flow, one of the contacts 2| and 22 will be closed,energizing the corresponding relay I9 or 20 and the corresponding coil25 or 26. The motor I2 is thereby caused to rotate in one direction orthe other depending upon the current flow through the relay ll. As longas the relay I! remains energized, lamp 16, which may be placed eitherat the remote point or at the receiver, will be lighted showing that thereceiver is in the process of being tuned.

When either of relays I9 or 20 is energized the energizing circuitincludes the coil 36. The coil 36 by attracting the armature 38 releasesthe disk 40 from the pendulum and allows the motor to rotate the gangcondenser unit ll until the arm in reaches a position on resistance 9corresponding to the position of the closed contact I6, balancing thebridge. When this condition is brought about relay I1 isdeenergized,'closed contact 2! or 22 is opened, relay 19 or 20 isde-energized, coil 36 is de-energized which allows spring ill to connectthe armature 38 to the disk ill stopping the motor by the inertia of thependulum arm 37 and weight M. This type of braking action prevents aninstantaneous stop of the disk to reducing shocks and jars and at thesame time stopping the rotating mechanism within tuning limits eventhough the action is slightly oscillatory, since the receiving circuitis inoperative as will be explained hereinafter.

The apparatus 5, it, and i shown within the dotted outline W may belocated at any convenient distance from the receiver. Each of thecontacts It may be preset to a particular broadcast wave length orstation and thereafter a pressure on any contact will bring in thatstation.

If, however, other stations are desired they may be tuned in under thecontrol of contact l5 which .may be in the form of the well known radiodial.

In the circuit just described, the resistance 30 performs two functions.It allows for the use of a high voltage across the potentiometers 5 and9 which would ordinarily burn out the sensitive relay IT. The voltagedrop across this resistance protects the relay. Furthermore when thecurrent flow is increased through it by the energization of the relayll, an increased grid bias is placed on the tube 33 blocking the signalstherethrougli and'preventing any reception in the loud speaker while therotating mechanism is moving and the, set is being tuned. By thisarrangement the receiver is made inoperative while the tuning operationis being accomplished. This blocking eiiect prevents relay. clicks andnoise produced by the motor from reaching the loud speaker. Thisblocking effect may be timed by the constants of condenser 42 andresistance 43 to be eiiective long enough to permit the rotatingcondenser mechanism to become stationary in spite of its oscillation dueto the pendulum brake.

Fig. 3 shows a single tube amplifier in the bridge circuit in which theplate impedance of the tube is in one arm of the bridge. The apparatusand circuit arrangement shown within the .dotted enclosure Y may besubstituted for that within the dotted enclosure X of Fig. 1, the pointsdesignated A, B, C, D, E and F representing where connections are to bemade with the other parts of Fig. 1. Variable contact is connected tothe grid of the tube 50 while the variable arm ll] of potentiometer 9 isconnected through grid biasing 10 battery 5! to filament of the tubev5i). A fixed resistance 52 and variable resistance 53 are shown in theplate circuit in shunt to the coil of relay IL. A high plate potentialsupply for the tube 50 is shown as a battery 55 shunted by apotentiometer composed of resistances 56 and 51.

The relay l'l operates as before on oppositely flowingpurrents due tothe unbalancing of the bridge composed of potentiometers 5 and 9. Whencurrent is caused to flow in one direction, the grid has an increasednegative bias while current flow in the opposite direction reduces thenormal bias placed on the tube by battery 5|. This change in the plateimpedance of the tube 50 changes the direction of flow of current Ithrough the polarized relay ll. For instance, with a high negative bias,the tube acts as an open circuit and raises the potential of the plateterminal to which the upper end of the coil ll is connected. Currentwill then flow downward through the coil of relay I'I due to the factthat resistances 52 and 53 in series with coil ll are in shunt withresistance 56 all of which have a common return to battery throughresistance 51. With a high positive grid bias the tube acts as a shortcircuit and current will flow in upward direction through the coil ofrelay I! due to the fact that the resistance ratio between theresistance 5'! and the tube 50 willthen be greater than the ratio ofresistance 56 to the sum of the resistances 52 and 53. The variableresistance 53 is required to adjust the relay when using difierent tubeswhich may have different characteristics. With this type of circuit onlycomparatively small voltages are required at the remote point of controland across the contacts. This permits the controlled receiver to belocated a long distance from the controlling unit.

Fig. 4 shows a. circuit similar to Fig. 3 except that it is adapted to apush pull arrangement of vacuum tubes which further increases thesensitiveness of control with small currents. The apparatus and circuitarrangement shown within the dotted enclosure Z may be substituted forthat within the dotted enclosure X of Fig. 1, the points designated A,B, C, D, E and F representing where connections are to be made with theother parts of Fig. 1. The grids of tubes 60 and 6| are connected tothearms l5 and ID, respectively, of the bridge formed by potentiometers60 5 and 9 and receive a bias from a battery 62. Plate potential isobtained from a battery 63. With this type of circuit a double windingis re- 7 quired on the relay to produce the opposite polarizationnecessary with alternate biasing on the push-pull tubes.

Although the invention as described above has been shown embodied in oneparticular system it is to be understood thatequivalent systems arecontemplated and the invention is to be limited only by the scope of theappended claims.

What is claimed is:

1. In a radio receiver ,having a plurality of electron tubes, means fortuning said receiver, means for actuating said tuning means, means 7located at a point remote from said receiver for controlling saidactuating means, and means operating responsive to actuation of saidcontrolling means continuously to change a circuit of one of saidelectron tubes to render the receiver inoperative during'all movementsof said actuating means whereby no clicks are produced in the receiverwhen said last mentioned means is operated to change a circuit of saidone of said electron tubes.

2. Remote control apparatus for tuning a receiver comprising .apotentiometer having prearranged taps, a plurality of correspondingmanual switches in parallel connection therewith, motor-mechanism fortunably adjusting said radio receiver, an electrically balanced networkincluding at least one electron tube of those which are comprised in thereceiving circuit of said radio receiver, said balanced networkcomprising conductors to the terminals of said potentiometer, aconductor common to said manual switches, a three-position relayresponsive to an unbalancing 01' said balanced network, a secondpotentiometer in said balanced network and mechanically associated withmotor-mechanism, and means having the dual function of selectivelyactuating said motor mechanism through said three-position relay andalso of silencing said receiver while it is being tuned.

3. Apparatus for tuning a radio receiver comprising a set of manuallyoperable switch keys remotely located from said receiver, each key beingselectable to render said receiver responsive to a desired frequency, areversibly operable motor-driven tuning device in said receiver, abalanced three-wire circuit connecting said switch keys with said tuningdevice, a variably tapped impedance associated with said switch keys atone end of said three-wire circuit, a potentiometer at the other end ofsaid three-wire circuit and mechanically adjusted by the operation ofsaid tuning device, a motor control relay included in said three-wirecircuit, an electron tube and a portion of the radio receiving circuitin shunt with said three-wire circuit, means whereby an unbalancing ofsaid three-wire circuit by manipulation of aswitch key is caused toalter the grid bias of said electron tube so as to silence said radioreceiver and another electron tube to impress an amplified current uponsaid relay thereby to control said tuning device, until the adjustmentthereof with its associated potentiometer restores the balance in saidthree-wire circuit.

4. Apparatus for tuning a radio receiver having a plurality of electrontubes and comprising a tuning device, means for operating the tuningdevice, means located at a point remote from said receiver forcontrolling the operating means, and meansioperating responsive toactuation of said controlling means to effect such a continuous changein grid bias in one of the electron tubes that said one tube is renderedinoperative whereby the said radio receiver is silenced dur-- ing allsetting movements of said tuning device and no clicks are produced insaid radio receiver.

5. Apparatus for tuning a vacuum tube radio receiver comprising areversibly operable motordriven tuning device, a balanced circuitarrangement for remotely controlling said tuning device to effect adesired setting thereof, electrontube and potentiometer-balancing meansin said circuit arrangement and means operable in response to theartificial unbalancing of the circuit arrangement to control thedirection and extent of movement of said tuning device and to effect achange of grid bias in the vacuum tube circuit of said receiver such asto silence the same.

6. In a radio receiver having a plurality of 5 electron tubes, eachhaving an input and an output circuit, means for tuning said receiver,means foractuating said tuning means, means located at a point remotefrom said receiver for controlling said actuating means, and means re-10 sponsive to operation of said controlling means for continuouslyaltering an electrical characteristic of one of said circuits of one ofsaid tubes thereby to make the receiver inoperative during all movementsof said actuating means whilst 15 maintaining the heating circuit ofsaid one electron tube, whereby no clicks will be produced in saidreceiver when the electrical characteristic of said one of said circuitsis altered.

7. An actuator for the tuning mechanism of 20 a radio receivercomprising a motor having an eddy-current disk provided with peripheralnotches, and remotely controlled field circuits,

. means including a latch engageable with one of said peripheral notchestor yieldingly arresting said eddy-current disk, said motor having apendulum arm to which said latch is pivotally. connected, a springnormally holding said latch in engagement with a notch of said disk, and1 means in circuit with said field circuits to re- 30 lease said latchfrom engagement with said disk, thereby permitting unimpeded operationof the motor.

8. An actuator for the tuning mechanism or a radio receiver comprising amotor having an 35 eddy-current disk and having a remotely controlledfield circuit, a pivotally mounted pendulum like weight member, meansnormally clutching said disk, to said member, remotely controlled meansto render said clutching means 40 ineffective whilst said field circuitis energized, and means operating upon de-energization of said fieldcircuit for causing said clutching means to clutch said disk to saidmember whereby the inertia of said member stops the rotation 45 of saiddisk.

9. An actuator according to claim 8, in which said disk has notches ofwedge-shaped crosssection around its periphery and said clutching meansincludes a lever pivotally connected 'to said weight member and having aportion shaped to enter one of said notches.

10. In a radio receiver having a plurality of electron tubes, means fortuning said receiver, means for actuating said tuning means, meanslocated at a point remote from said receiver for controlling saidactuating means, and means rendered effective in response to actuationof said controlling means continuously to change a charc0 acteristic ofone of said electron tubes thereby to render the receiver inoperativeduring all movements of said actuating means whereby no clicks areproduced during the operation of said last mentioned means. 65

11. In a radio receiver having a plurality of electron tubes, means fortuning said receiver, means for actuating said tuning means, meanslocated at a point remote from said receiver for controlling saidactuating means, and means rendered effective in response to actuationof said controlling means continuously to increase the input impedanceof one of said electron tubes to a finite value as to render thereceiver inoperative during movement of said actuating means v wherebyno clicks are produced during the operation of said last mentionedmeans.

12. An actuator for the tuning mechanism of a radio receiver comprisinga motor having an eddy-current disk fixed to a rotatable shaft andhaving remotely controlled field circuits, a pendulum arm pivotallymounted at one end on said shaft, means normally clutching said disk tosaid pendulum arm, remotely controlled means to render said clutchingmeans ineffective whilst said field circuit is energized, and meansoperating upon de-energization of said field circuit to cause saidclutching means to clutch the disk to said pendulum arm whereby rotationof said disk is stopped by the inertia of said pendulum arm.

13. In a radio receiver having a plurality of electron tubes, one ofsaid tubes having a plurality of electrodes including a cathode, ananode and a grid, means normally maintaining said grid at apredetermined potential with respect to said cathode, means for tuningsaid receiver, means for actuating said tuning means, means located at apoint remote from said receiver for controlling said actuating means,and means operating responsive to actuation of said controlling meanscontinuously to alter said potential of said grid to a value so negativeas to render one tube inelectron tubes, one of said tubes having aplurality of electrodes including a cathode, an anode and a grid, asource of direct current, a resistance element, connections between saidsource, said resistance element and said grid for normally maintainingsaid grid at a predetermined biasing potential, means 'for tuning saidreceiver,

means for actuating said tuning means, means located at a point remotefrom said receiver for controlling said actuating means, and meansoperating responsive to actuation of said controlling means to increasethe flow of current from said source through said resistance element 20whereby the biasing potential of said grid is increased negatively tosuch a value as to render said one electron tube inoperative as atranslating device and thereby silence said radio receiver during aselected setting movement of said 25 tuning device.

LOUIS WILLIAM REINKEN.

